Flexible hoses formed from corrugated metal tube are used in many applications where the hose is exposed to severe conditions or where the nature of the material conveyed through the hose requires the use of metal tubing. Advantageously, the corrugations lend some degree of flexibility to the metal tube. Typical uses of these hoses include applications where the hose is exposed to extreme hot and cold temperature conditions, where high pressure gas or liquid is transported through the hose, or when fluid permeability is a concern, such as in gas piping systems, refrigeration systems or the transport of chemical materials. These hoses also provide flexibility to fixed piping systems, for example, where adjacent fixed pipes must be joined together, and help to reduce vibrations in dynamic environments, such as various heavy machinery or automotive environments, all while maintaining integrity in these rigorous applications.
With flexible hoses formed from corrugated metal tube, it is of utmost importance to ensure that the hoses are constructed in a fluid tight manner, particularly at locations where fittings are joined to the hose for coupling the hose to a fluid conveying structure or to another hose. In the past, various fittings have been secured to the corrugated metal tube of flexible hoses by welding, brazing, or other fusion-type processes, or by deforming the corrugated metal tube to create a flange which may be mechanically clamped to a fitting, such as by a screwed compression assembly. For example, U.S. Pat. No. 6,276,728 is directed to a fitting for use with corrugated tubing wherein the tubing is deformed when it is secured to the fitting. U.S. Pat. No. 5,638,869 is directed to a hose connection that is both crimped and welded to secure a corrugated metal hose to the fitting. These prior fittings are generally costly and time consuming to install and are prone to inconsistencies stemming from the varied levels of skill of persons installing the fittings. These variations result in inconsistent quality of the resulting hose assemblies. Accordingly, there is a need for a fitting that can be used with flexible hoses formed from corrugated metal tubes which overcomes these and other drawbacks of the prior art.